Meca Renata, Balbo Bruno E, Ormanji Milene Subtil, Fonseca Jonathan M, Iannuzzi Leandro R, Santana Costa Eliene, Onuchic Luiz F, Heilberg Ita Pfeferman
Nephrology Division, Universidade Federal de São Paulo, São Paulo, Brazil.
Nephrology Division, Universidade de São Paulo, São Paulo, Brazil.
Cell Physiol Biochem. 2019;52(5):1061-1074. doi: 10.33594/000000072.
BACKGROUND/AIMS: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst formation and growth, leading to end-stage renal disease. A higher kidney volume is predictive of a more accelerated decline in renal function. This study aimed to examine the effects of caffeine, a phosphodiesterase inhibitor, on the progression of cystic kidney disease in a mouse model orthologous to human disease (Pkd1:Nestin).
Caffeine was administered to male cystic (CyCaf) and noncystic (NCCaf) mice (Pkd1) from conception and at the postweaning period through 12 weeks of life (3 mg/d), while control animals consumed water (CyCtrl and NCCtrl). Renal ultrasonography was performed at 10 weeks of life to calculate total kidney volume and cystic index. At the end of the protocol, blood and urine samples were collected for biochemical analysis, and animals were euthanized. Kidneys were harvested to obtain renal tissue for determinations of adenosine 3´5´-cyclic monophosphate (cAMP) by an enzymatic immunoassay kit and phosphorylated extracellular signal-regulated kinase (p-ERK) by Western blotting. Renal fibrosis (picrosirius staining), renal cell proliferation (ki-67 immunohistochemistry) and apoptotic rates (TUNEL analysis) were also determined.
At 12 weeks, CyCaf mice exhibited higher serum urea nitrogen, renal cystic index, total kidney volume, kidney cell proliferation, apoptosis and fibrosis compared with CyCtrl mice. Serum cystatin C was significantly higher in CyCaf than in NCCaf and NCCtrl mice. CyCaf mice had higher total kidney weight than all other groups but not higher heart and liver weight. The levels of cAMP and p-ERK did not differ among the groups.
Caffeine consumption from conception through 12 weeks led to increased cystic index and total kidney volume and worsened renal function in Pkd1-deficient cystic mice, suggesting that high consumption of caffeine may contribute to a faster progression of renal disease in ADPKD.
背景/目的：常染色体显性遗传性多囊肾病（ADPKD）的特征是囊肿进行性形成和生长，最终导致终末期肾病。肾体积较大预示着肾功能下降加速。本研究旨在探讨磷酸二酯酶抑制剂咖啡因对与人类疾病同源的小鼠模型（Pkd1:Nestin）中多囊肾病进展的影响。
从受孕开始，对雄性囊性（CyCaf）和非囊性（NCCaf）小鼠（Pkd1）在断奶后至12周龄期间给予咖啡因（3mg/d），而对照动物饮用自来水（CyCtrl和NCCtrl）。在10周龄时进行肾脏超声检查，以计算总肾体积和囊肿指数。在实验方案结束时，采集血液和尿液样本进行生化分析，然后对动物实施安乐死。摘取肾脏获取肾组织，通过酶免疫分析试剂盒测定3´5´-环磷酸腺苷（cAMP），通过蛋白质印迹法测定磷酸化细胞外信号调节激酶（p-ERK）。还测定了肾纤维化（天狼星红染色）、肾细胞增殖（ki-67免疫组织化学）和凋亡率（TUNEL分析）。
在12周时，与CyCtrl小鼠相比，CyCaf小鼠的血清尿素氮、肾囊肿指数、总肾体积、肾细胞增殖、凋亡和纤维化水平更高。CyCaf小鼠的血清胱抑素C显著高于NCCaf和NCCtrl小鼠。CyCaf小鼠的总肾重量高于所有其他组，但心脏和肝脏重量无差异。各组间cAMP和p-ERK水平无差异。
从受孕到12周龄期间摄入咖啡因会导致Pkd1基因缺陷的囊性小鼠的囊肿指数和总肾体积增加，肾功能恶化，这表明高咖啡因摄入量可能会促使ADPKD患者的肾病进展加快。
